[Wien] Virtual-crystal

[Fecher, Gerhard]

x=0.5 of whatever maybe too much for VCA

If you change for example the electrons at a transition metal atom, then you should change the number of d electrons in case.inst
(they are different for each TM atom, and the occupation of d3/2 and d5/2 depends on kind of atom as well as spin polarised or not).

Did you check what numbers change in the input files when you go from x=0.0 to x=1.0 (or from one atom to a neighbouring) ?

By the way, if you add 1 electron to Manganese (Z=25) then you have iron (Z=26).

To go back to the beginning of the e-mail, VCA does not distinguish the types of atoms,
think about whatelse mixtures you model with the same numbers. Is that what you wanted to have ?



Ciao
Gerhard

DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
"I think the problem, to be quite honest with you,
is that you have never actually known what the question is."

====================================
Dr. Gerhard H. Fecher
Institut of Inorganic and Analytical Chemistry
Johannes Gutenberg - University
55099 Mainz
________________________________________
Von: wien-bounces at zeus.theochem.tuwien.ac.at [wien-bounces at zeus.theochem.tuwien.ac.at]" im Auftrag von "Jihoon Park [jpark61 at crimson.ua.edu]
Gesendet: Mittwoch, 22. August 2012 06:09
An: wien at zeus.theochem.tuwien.ac.at
Betreff: [Wien] Virtual-crystal

Dear Users,


I am trying to perform a calculation using "virtual-crystal" method.
I have found the way to do this and it is as below.

- run through inil_lapw using default atomic numbers
- edit nuclear charges in case.struct
- edit corresponding occupancies in case.inst
- edit the total number of electrons in case.in2
- run SCF circle


But I do not understand a few things.

First, I do not know how I should change the occupation number. I have looked up the manual, but still confused.
Just say that I want to do x = 0.5 for example, then what should I edit? There are numbers like "1.0, 2.0, 3.0 and so on..."

Second, if I want to add one more electron in the unit cell (two f.u., therefore x = 0.5), should I just do the # of electron + one in case.in2?
For example, if the current # of electrons is 25, should I put the # of electrons as 26?


All my best,
Jihoon Park

--
Graduate Research Assistant
Magnetic Materials and Device Laboratory
Department of Electrical and Computer Engineering
101 Houser Hall, Box 870286
The University of Alabama
Tuscaloosa, Alabama 35487
Tel (205)348-3759
Fax (205)348-6959

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